Abstract:

Pot experiment was conducted to investigate the effects of biodegradable chelators–
Glutamic acid N, N-diacetic acid tetra sodium salt（GLDA）and iminodisuccinic acid sodium salt（IDS）
added at different concentrations（3，6，9，12 and 15 mmol · kg-1）on seed germination，growth and
physiology of Festuca arundinacea Schreb. seedlings. The results showed that the addition of GLDA and
IDS inhibited seed germination of F. arundinacea，especially at high concentrations. The addition of
GLDA and IDS at low concentrations increased aboveground biomass ， but reduced it at high
concentrations. The highest aboveground biomass was found at the chelator treatment of 6 mmol · kg-1，
which was significantly higher than those in the other chelator treatments. The addition of GLDA and IDS inhibited root growth of F. arundinacea，especially at high concentrations. Compared with the control，
chelators at low concentrations（3，6 and 9 mmol · kg-1）had no significant effects on chlorophyll and
carotenoid contents. However，chelators at high concentrations significantly decreased chlorophyll and
carotenoid contents. The activities of SOD and CAT increased and then decreased with the increase in
chelator concentration，while the POD activity and MDA content increased constantly with the increase in
chelator dosage. The results indicated that the addition of GLDA and IDS may form stress for F.
arundinacea，and the plants could develop resistance to the stress by increasing the activities of antioxidant
enzymes. Thus，when GLDA and IDS are applied in remediation of soil polluted by heavy metals，they
should be applied at a low concentration（6 mmol · kg-1）and should be added several days before plants are
harvested or added at a low dosage in multiple times.

Key words: turfgrass, biodegradable chelator, GLDA, IDS, physiology